Here are several prominent libraries that handle browser detection as of May 2019.


### [Bowser][1] by lancedikson - 3,761★s - Last updated May 26, 2019 - 4.8KB





    var result = bowser.getParser(window.navigator.userAgent);
    console.log(result);
    document.write("You are using " + result.parsedResult.browser.name +
                   " v" + result.parsedResult.browser.version + 
                   " on " + result.parsedResult.os.name);



    <script src="https://unpkg.com/bowser@2.4.0/es5.js"></script>



<i>*supports Edge based on Chromium</i>

---

### [Platform.js][2] by bestiejs - 2,250★s - Last updated Oct 30, 2018 - 5.9KB





    console.log(platform);
    document.write("You are using " + platform.name +
                   " v" + platform.version + 
                   " on " + platform.os);



    <script src="https://cdnjs.cloudflare.com/ajax/libs/platform/1.3.5/platform.min.js"></script>







### [jQuery Browser][4] by gabceb - 504★s - Last updated Nov 23, 2015 - 1.3KB





    console.log($.browser)
    document.write("You are using " + $.browser.name +
                   " v" + $.browser.versionNumber + 
                   " on " + $.browser.platform);



    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-browser/0.1.0/jquery.browser.min.js"></script>






### [Detect.js (Archived)][3] by darcyclarke - 522★s - Last updated Oct 26, 2015 - 2.9KB 





    var result = detect.parse(navigator.userAgent);
    console.log(result);
    document.write("You are using " + result.browser.family +
                   " v" + result.browser.version + 
                   " on " + result.os.family);



    <script src="https://cdnjs.cloudflare.com/ajax/libs/Detect.js/2.2.2/detect.min.js"></script>







### [Browser Detect (Archived)][5] by QuirksMode - Last updated Nov 14, 2013 - 884B





    console.log(BrowserDetect)
    document.write("You are using " + BrowserDetect.browser +
                   " v" + BrowserDetect.version + 
                   " on " + BrowserDetect.OS);



    <script src="https://kylemit.github.io/libraries/libraries/BrowserDetect.js"></script>




--- 

## Notable Mentions:

* [WhichBrowser][6] - 1,355★s - Last updated Oct 2, 2018
* [Modernizr][7] - 23,397★s - Last updated Jan 12, 2019 - To feed a fed horse, feature detection should drive any [canIuse][8] style questions.  Browser detection is really just for providing customized images, download files, or instructions for individual browsers.

## Further Reading

* [**Stack Overflow** - Browser detection in JavaScript?][9]
* [**Stack Overflow** - How to detect Safari, Chrome, IE, Firefox and Opera browser?][10]


  [1]: https://github.com/lancedikson/bowser
  [2]: https://github.com/bestiejs/platform.js/
  [3]: https://github.com/darcyclarke/Detect.js
  [4]: https://github.com/gabceb/jquery-browser-plugin
  [5]: https://web.archive.org/web/20131114025336/http://www.quirksmode.org:80/js/detect.html
  [6]: https://github.com/WhichBrowser/Parser-PHP
  [7]: https://github.com/Modernizr/Modernizr
  [8]: https://caniuse.com/
  [9]: https://stackoverflow.com/q/2400935/1366033
  [10]: https://stackoverflow.com/a/49581520/1366033

I've been searching around for code that would let me detect if the user visiting the website has Firefox 3 or 4. All I have found is code to detect the type of browser but not the version.

How can I detect the version of a browser like this?

How can you detect the version of a browser?

Expanding on scrappedocola/renergy's idea, you can turn the [JavaScript into a bookmarklet][1] that executes against the `javascript:` uri so the code can be re-used easily across multiple pages without having to open up the dev tools or keep anything on your clipboard.  

Just run the following snippet and drag the link to your bookmarks/favorites bar:





    <a href="javascript: var el = document.querySelectorAll('style,link');
             for (var i=0; i<el.length; i++) {
               el[i].parentNode.removeChild(el[i]); 
             };">
      Remove Styles 
    </a>



* I would avoid looping through the thousands of elements on a page with `getElementsByTagName('*')` and have to check and act on each individually.
* I would avoid relying on jQuery existing on the page with `$('style,link[rel="stylesheet"]').remove()` when the extra javascript is not overwhelmingly cumbersome.

[1]: http://www.dev-hq.net/posts/1--create-javascript-bookmarklet

Is there any way I can disable all external CSS in a browser (Firefox, Chrome...)?

When using slower internet connection, sometimes only the bare HTML is loaded by the browser without the CSS info. It looks like the page has been laid raw on the screen. You would have noticed this with StackOverflow too.

I want to make sure that my web page shows up OK even if the CSS files are not loaded.

I didn't mean I want to convert external CSS to inline. But I want a way to explicitly disable all CSS from the browser so that I can reposition my elements in a better, readable way.

I know I can remove the &lt;link rel='stylesheet'&gt; entries, but what if I have a lot of linked pages?